Operators of wireless communication networks have for a longer time used cellular (also called mobile) communication technologies like Global System for Mobile Communications, GSM, Code Division Multiple Access 2000, CDMA 2000, Wideband CDMA, W-CDMA and Long Term Evolution, LTE. In addition, the operators are also using Wireless Local Area Network communication technology, WLAN. The WLAN communication technology is typically based on the IEEE 802.11 standard. However, other similar standards may apply. The WLAN may also be called a Wi-Fi network. The operators are today mainly using WLAN to offload traffic from the mobile networks but the opportunity to improve end user experience regarding performance is also becoming more important. Most of current WLAN deployments are totally separate from the mobile networks, and are to be seen as non-integrated. The usage of WLAN is mainly driven due to the free and wide unlicensed spectrum, and the increased availability of WLAN in user equipments, UEs, like smart phones and tablets. The end users are also becoming more and more at ease with using WLAN for example at offices and homes. For these reasons, there is an interest of trying to integrate WLAN into mobile networks.
Exemplary methods for integrating WLAN in a radio access network, RAN, part of a mobile network are discussed in “Study on WLAN/3GPP radio interworking (Release 12), 3GPP TR 37.834 V12.0.0 (2014-018)”. In the method called as “Solution 3”, the decision for the UE to access WLAN is made by the RAN. A UE that is connected to a RAN and receives a signal from a predefined WLAN has been instructed to send to the RAN a measurement report comprising signal quality measurements performed on the signal received from the WLAN. Based on the reported WLAN measurements and possibly also RAN measurements and information such as available capacity in the RAN, the RAN may send a steering command message to the UE to perform access selection and/or traffic steering to the WLAN, i.e. to connect to the WLAN.
However, a drawback with such a method is that the WLAN signal quality measurements that the UE reports to the RAN are for downlink, DL, only. The WLAN uplink, UL, information is not available until the UE starts connecting to the WLAN. As separate transmitter/receiver pairs are used for UL and DL transmission, the UL and DL signal quality measurements may differ a lot and could therefore impact the decision whether the UE would finally be connected to the WLAN or not. If the UL signal quality is worse than the DL signal quality this may result in a final rejection of the UE to the WLAN during connection to the WLAN.
Consequently, there is a need for another way of integrating WLAN in RAN such that both UL and DL signal quality measurements for the WLAN are taken into consideration when deciding to connect a UE to a WLAN.